Greubel Forsey marks 13 years of watchmaking in 2017. For nearly that long, founders Robert Greubel and Stephen Forsey have been secretly working on the horological chef d’oeuvre that made its debut at SIHH 2017: the brand’s first Grande Sonnerie wristwatch. Here is a detailed look at the watch, along with some hands-on photos taken at the timepiece’s U.S. debut.

It required 11 years of research and development, the assembly of 935 parts for the movement and case, and the filing of two patents, but this year, Greubel Forsey ? which in its relatively short existence has created numerous boldly inventive (and in many cases, industry-award-winning) haute horlogerie inventions ? finally joins the very exclusive ranks of watch maisons that offer a grande sonnerie. A grande sonnerie is among the highest echelon of watch complications, featuring a chiming mechanism that strikes, on its own, in passing, every hour, and repeats the hours and indicates the quarters at each quarter-hour; this differentiates a grand sonnerie from, and puts it on a higher plane of complexity than, a minute repeater, which chimes the hours, quarters, and minutes only on demand. Greubel Forsey has equipped its Grande Sonnerie timepiece with a specially developed acoustic resonance cage, which helps the watch’s cathedral gongs produce a sound the brand describes as “extremely pure,” and incorporated 11 security functions into the mechanism. The ergonomically designed, ...